Water Leaks in Stone Fireplaces

Warning Signs

• There are several signs that you have a leak or some sort of moisture problem in your fireplace. An obvious sign is water beading or dripping down the fireplace, either on the outside stone or down the chimney flue. You may also see water stains in grout areas where moisture has penetrated. Efflorescence is another word for leeching where water soaks through the joints and dissolves the salts, which are then brought to the surface and leave salt deposits. Consult a chimney expert if you see any of these signs of water.

Locate the Problem

• Find the problem before you deal with the stains and work to waterproof the stone. In some cases, it isn't even the stone or mortar causing the leak. Cracks or holes in the crown at the top of the chimney may allow rain moisture into the chimney. Another problem may be the seal between the roof and the chimney, allowing moisture to flow down through the seam between the two. This often creates not just a leaky fireplace but water issues in adjacent walls and ceiling structures.

Fix the Leak

• Fix the source of the leak before starting any cleanup or preventative actions. If the cap is damaged or corroded, replace it. Patching it may only be a temporary solution and lead to bigger water problems later on. Reseal all rooftop seams and make sure the roof is not in need of repair itself, leading to water pooling around the fireplace. A qualified chimney expert will inspect every part of your stone fireplace and chimney and fix any problems. Use a sealant that is approved for chimneys. Unlike stone floors, chimneys need to remain porous to vapor. Buy a vapor-penetrating sealant made especially for fireplaces and chimneys.

Clean Up

• Stains in the grout may be hard to clean since grout is porous and the stain sets deep in the masonry material. Use a mixture of one part tri-sodium phosphate to 20 parts water and scrub the stains. Clean the entire fireplace with the solution as well to remove any dirt, grime and soot on the stone surface. A good cleaning keeps the coloring on your stone fireplace even.